High speed transfer drive

ABSTRACT

A cam flange extends radially outward from a cylindrical body, and followers are mounted on opposite sides of the flange for continuous uniform direction rotation of the followers as the cam rotates, and the followers move slides.

Write tates Patet 1 1 1 1 3 McCaughey 1 51 Apr. 24, 1973 HIGH SPEED TRANSFER DRIVE [56] References Cited [76] Inventor: Stuart H. McCaughey, PO. Box UNITED STATES PATENTS 255, C k ll R d, fg g gjg 0a 3,155,217 11/1964 Cross ..214/1 B 3,528,575 9/1970 McCaughey 214/1 BB [22] Filed: Nov. 30, 1970 Primary ExaminerWilliam F. ODea l [2 1 Appl NO 93 697 Assistant Examiner-Wesley S. Ratliff, Jr.

Related US. Application Data Attorney-Littlepage, Quaintance, Wray & Aisenberg [62] Division of Ser. No. 25,725, April 6, 1970. [57] ABSTRACT [52] US. Cl ..74/56 A cam flange xtends radially outward from a cylindri- 1511 11m. Cl ..F16h 25/12 cal body, a followers are u d n pposit s des [58] Field f Sear h 74/56; 214/1 BB, 1 BT of the flange for continuous uniform direction rotation of the followers as the cam rotates, and the followers move slides.

2 Claims, 2 Drawing Figures PATENTEBAPR24 1975' 3.728302 sum 1 OF 2 FIG. I

STUART H.. MOCAUGHEYYV HIGH SPEED TRANSFER DRIVE This application is a division of Patent Application Ser. No. 25,725, filed on Apr. 6, 1970, by Stuart H. McCaughey for Horizontal High Speed Transfer.

BACKGROUND OF THE INVENTION Very high speed press operations are made possible by new tool materials and press designs. One area which has limited the speed of press operations is the transfer apparatus which is used to feed articles from station to station in presses. Article feed or transfer apparatus has heretofore employed springs which require excessive operational times to move a part from one position to another. During the rapid accelerations while being transferred between work stations, work pieces which are not well engaged and held tend to float and misalign, jamming the machinery, or causing high rejection rates, and necessitating high percentages of inspection and sampling. Forces which cause floating and misalignment increase geometrically with increasing cyclic speeds.

Movements must be very accurate in all transfers. In high speed transfers, the accuracy of the transfer movements becomes critical. Play or backlash in transfer apparatus causes many problems which cannot be tolerated in high speed equipment. Because of the increased accelerations, many conditions which are completely workable at low speeds, become destructive at high speed. For example, the periodic reversing of direction of a cam follower roller may be tolerated at low cyclic speeds. When the follower is cycled back and forth at high speeds, velocities of the roller and cam become high, and braking of the roller against the cam face becomes a serious problem upon each reversal of direction.

SUMMARY OF THE INVENTION The high speed article feed or transfer apparatus described herein is intended to overcome problems associated with high speed transfer operations. The present apparatus is capable of operation at 350 cycles per minute and beyond. Each interrelated movement is produced by positively interlocked elements which permit relative motion only in the intended directions.

Timing belts are employed to drive the transfer apparatus directly from a rotating shaft which drives the press. A timing belt drives a gear pulley which is attached to a cam drive shaft. Two cylindrical cams are keyed on the drive shaft with the cams thereon in phased displaced relationship. In a preferred form, the cams are constructed with radially extended cam flanges which are curved to create the camming or reciprocal motion. Cam follower rollers are positioned on both sides of the cam flange so that the rollers continually rotate in a uniform direction. There is no braking, stopping and reversing direction of the cam follower rollers. The source of wear and backlash is thus eliminated.

The cam flange is preferably constructed with a tapering cross section so that its widest dimension is at its base and its smallest dimension is at its axially outward extremity. Follower rollers are tapered so that their smallest dimension is nearest the cam drive shaft. Where the cam flange s linear speed is least, it contacts the smallest circle of the follower roller. Where the cam flanges linear speed is greatest, it contacts the largest circle on the follower. Angular speedsof the follower are constant notwithstanding that the linear speed of the cam and follower increase incrementally with the increased distance from the center of the cam and drive shaft. Thus, there is no frictional cam drive shaft follower interface, and no backlash is developed.

Slides which support the cam follower axle ride on surfaces which are lubricated by zigzag lubricating channels. Upper surfaces of the slides are sloped to match the sloping retainer surfaces, which hold the slides inward toward the drive shaft.

The cam and slide farther from the drive pulley control the forward and rearward motions of the grooved cam bars which move the carriers in and out. The cam and slide nearer the drive pulley reciprocate the carrier support and carrier bars in which work piece engaging fingers or grooves are formed. Since the latter apparatus is the heavier of the reciprocating parts, and since it has the longest cyclic movements, acceleration forces are greater than in other parts of the transfer. Consequently, the carrier support and slide connections for the drive rod are aligned as closely as is convenient. Angular movements of the drive rods interconnecting the carrier support and slide are kept to a minimum.

The cam and slide which are further away from the drive pulley are similar to the before-described cam and slide. Connecting rods extend forward from the latter slide and connect to the lower flanges of two cranks with parallel vertical axles. Outer ends of the upper flanges of the cranks are connected to cam bars. The cam bars drive the parallel carrier bars in and out between article engaging and disengaging positions before the carrier bars are advanced or are withdrawn. The cam bars are mounted between upper and lower cam slides. In a preferred form of the invention the cam bars have apertures which are angularly oriented with respect to longitudinal directions of the bars. Ball bearing mounted wheels are placed within the apertures for rotating on axles mounted between the slide plates. As the cam bars are reciprocated longitudinally, the slope of the apertures causes the cam bars to be translated at angles to the longitudinal directions.

The carrier bars are attached to the cam bars to permit free relative sliding movement therebetween in longitudinal directions of the bars. The interconnections between the bars prevent relative transverse movement. Consequently, the carrier bars undergo the transverse component of the angular movement of the cam bars, while the cam bars slide longitudinally with respect to the carrier bars. The carrier bars move longitudinally with the cam and slide which are closest the drive pulley and move in and out according to movements of the other cam and slide which are communicated through the cam bars.

One object of the invention is the provision of a high speed horizontal transfer apparatus with positively controlled interrelated movements between elements.

Another object of the invention is the provision of flanged cams with double tapered roller slide interconnections.

These and other objects of the invention will be apparent from the disclosure which is found in the foregoing and detailed specification portions as well as in the claims and in the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-section elevation of the rotating to reciprocating drive apparatus showing the tapered radial cam flange and double tapered follower rollers.

FIG. 2 is a cross-sectional end elevation of the radial flange cam and follower.

DETAILED DESCRIPTION OF THE DRAWINGS Transfer drive apparatus is generally indicated in FIGS. 1 and 2. A timing belt turns a gear 110 in a direct relation to cyclic operations of a press. Preferably, the timing belt is connected to a press drive shaft which, for example, may extend outward from an upper portion of a press. Pulley 110 is keyed to transfer drive shaft 108. Also keyed to the drive shaft is a first cylindrical cam body 120 which has a cam flange 128 radially extending therefrom. Cam flange 124 forms a smooth curve, with portions of the cam positionally varying with respect to an axial direction of drive shaft 108. In a preferred form of the cam, thickness at root 126 is greater than thickness at radial outward extremity 128. Cam 120 reciprocates slide 134 by the action of two wheels 130, which are mounted on either side of the cam flange 124, and which are connected with axles 132 to slide 134. A second cylindrical body 160 supports a radially extending cam flange 164 which drives follower rollers 166. The cam follower rollers are mounted on axles 168, which are mounted in slide 170, and which extend downward therefrom on opposite sides of cam flange 164. Rods 40 have first ends connected to pins which extend outward from opposite sides of slide 170. Forward ends of rods 40 are connected through clevises to carriers. Rods 40, slide 170 and cam 160 reciprocate the carriers forward and rearward. Inward and outward motion is imparted to carrier bars by cam bars. The latter are driven back and forth through linkage which is moved by slide 134 and cam 120. Rods 62 are connected to a forward edge of slide 134.

Referring to FIG. 1, a cam base which is part of the fixed transfer frame is configured similar to well-known crankcases. The upper surface of the base or frame is a sliding surface with oil groove lubrication. Base 100 is sealed at both ends 102 and 104, where tapered roller bearings support the shaft for rotation.

One end of drive shaft 108 mounts a gear-toothed pulley which is keyed to the drive shaft. A timing belt drives the pulley 110.

The cylindrical body 122 of a first drive cam 120 is keyed to drive shaft 108 at a remote location thereon from the drive pulley. A cam flange 124 extends radially from body 122 and smoothly incrementally varies axial position around the circumference of the body.

Cam flange 124 is tapered from a maximum cross-sec surfaces are engaged by complimentary sloping surfaces 144 of retainers 146 which are lubricated by oil passages 148. Rod 62, which drives the crank and cam bar, is connected to a plate 150 secured at the forward end of slide 134.

A second cam is connected to the drive shaft near the drive pulley. The second, cam, cam followers and slide are configured closely similar to the first cam, and the identification numbers are similar to identify the elements. One difference between cam 120 and cam 160 is that the latter has a greater cyclic travel. Cam flange 164 drive cam followers rollers 166. The rollers are mounted on shaft 168 in slide 170. Oil channels 142 and 148 serve sliding surfaces 140 and 144 as shown in FIG. 4. Slide 170 is connected to rod 40 which drives the carrier apparatus.

Although the invention has been described with reference to specific embodiments, it will be appreciated by those skilled in the art that other embodiments may be constructed without departing from the teachings of the invention. The scope of the invention is defined only in the following claims.

That which is claimed is:

1. Continuous rotating press drive to intermittent reciprocating transfer motions transforming apparatus comprising a base, a drive shaft mounted for rotation in the base, rotating drive means connected to the drive shaft for continuously rotating the shaft, a cylindrical body mounted on the drive shaft for rotation therewith, a planar sliding surface mounted on the base radially outward from the cylindrical body and tangentially parallel to the body, a slide mounted on the sliding surface for relative sliding with respect to the base, a first pair of first and second spaced axles connected to the slide and extending therefrom radially inward toward the drive shaft, a first axially varying cam flange radially extending from a surface of thecylindrical body and having smooth variations between fixed axial positions with respect to the drive shaft, the first cam flange extending adjacent the first pair of first and second axles, first and second cam follower rollers mounted respectively on the first and second pairs of axles and engaging the cam flange for intermittently moving the slide along the sliding surface in response to axial variations of the cam flange with rotation of the drive shaft by the drive means, wherein the slide is configured for connection to a workpiece advancing linkage, for intermittently moving the linkage in response to intermittent movements of the slide, and further comprising a second slide mounted on the sliding surface, a second pair of axles extending inward from the second slide radially toward the cylindrical body, cam follower rollers mounted on the axles, and a second cam flange axially displaced on the body from the first cam flange and radially extending from the cylindrical body between the rollers on the second pair of axles, the second cam flange having smooth variations between fixed axial positions, which are angularly displaced from fixed axial positions of the first cam flange, for intermittently moving the second slide in time displaced relation to the first slide, wherein the second slide is configured for connection to a second linkage for engaging and disengaging a workpiece, and wherein the first slide advances and retracts the second linkage.

2. The apparatus of claim 1 wherein the slides define sloping surfaces remote from the sliding surface, and further comprising means connected to the frame and fitted over the sloping surfaces for holding the slides inward toward the sliding surface. 5 

1. Continuous rotating press drive to intermittent reciprocating transfer motions transforming apparatus comprising a base, a drive shaft mounted for rotation in the base, rotating drive means connected to the drive shaft for continUously rotating the shaft, a cylindrical body mounted on the drive shaft for rotation therewith, a planar sliding surface mounted on the base radially outward from the cylindrical body and tangentially parallel to the body, a slide mounted on the sliding surface for relative sliding with respect to the base, a first pair of first and second spaced axles connected to the slide and extending therefrom radially inward toward the drive shaft, a first axially varying cam flange radially extending from a surface of the cylindrical body and having smooth variations between fixed axial positions with respect to the drive shaft, the first cam flange extending adjacent the first pair of first and second axles, first and second cam follower rollers mounted respectively on the first and second pairs of axles and engaging the cam flange for intermittently moving the slide along the sliding surface in response to axial variations of the cam flange with rotation of the drive shaft by the drive means, wherein the slide is configured for connection to a workpiece advancing linkage, for intermittently moving the linkage in response to intermittent movements of the slide, and further comprising a second slide mounted on the sliding surface, a second pair of axles extending inward from the second slide radially toward the cylindrical body, cam follower rollers mounted on the axles, and a second cam flange axially displaced on the body from the first cam flange and radially extending from the cylindrical body between the rollers on the second pair of axles, the second cam flange having smooth variations between fixed axial positions, which are angularly displaced from fixed axial positions of the first cam flange, for intermittently moving the second slide in time displaced relation to the first slide, wherein the second slide is configured for connection to a second linkage for engaging and disengaging a workpiece, and wherein the first slide advances and retracts the second linkage.
 2. The apparatus of claim 1 wherein the slides define sloping surfaces remote from the sliding surface, and further comprising retaining means connected to the frame and fitted over the sloping surfaces for holding the slides inward toward the sliding surface. 